A novel method of wavelength modulation for atomic spectrometry—some preliminary experiments

Abstract

The method of wavelength modulation most commonly used in atomic spectrometry employs an oscillating refractor plate driven by a scanning motor. A new mechanical arrangement is described, which involves a rotating quartz mechanical chopper. This quartz chopper is composed of four quadrants of different thickness, which refract radiation by different degrees. The rotating quartz chopper is placed inside the monochromator in a position similar to that used for oscillating refractor plates. Efficient wavelength modulation is achieved. However, the rotating quartz chopper has the advantage that a good square-wave modulation function is obtained.